Has president Trump or his administration responded to these attacks? Have the perpetrators been arrested and charged, and/or are there official investigations into this?
There have been several incidents, and several responses, but the most widely covered seems to be the case of the CNN reporter, Omar Jimenez and his crew, who were arrested and released about an hour later. Today, the Minnesota governor personally apologized to the reporter, and accepted responsibility for the incident.
One initial explanation for the arrest seems to be that the initial version of an emergency curfew ordered in Minneapolis did not make an exception for reporters, though this was later addressed by amending the curfew.
I'm not sure why you think the Federal Government would be involved in this case as it is really at the state level. Crowd control actions in Washington DC, particularly those by the U.S. Park Police, might be a notable exception. The incident described in @divibisan's answer will be worth watching.
Attacks on foreign journalists reporting in the US seem to have drawn a stronger response, since they have a government willing to fight on their behalf. For example, 2 Australian journalists were recently attacked in Washington DC by, reportedly, the United States Park Police.
This attack has drawn sharp criticism from the Australian Prime Minister and led to a formal complaint and demand for an investigation:
The Australian prime minister has called for an investigation into how police officers treated two Australian journalists who were covering a protest outside the White House on Monday.
The two journalists, on assignment for Australia’s Channel 7, one of the nation’s major networks, were among the members of the news media covering the demonstration as President Trump threatened a crackdown on protests in a speech delivered from the Rose Garden starting at 6:43 p.m.
“I understand that Channel 7 will make a formal police complaint asking to have the matter investigated,” Mr. Sinodinos [the Australian ambassador to the United States] said. “We are in discussion with the State Department, and they have offered assistance to identify where the complaint should be targeted.”
While the US ambassador has only made vague public statements, 2 officers have been placed on desk duty and an investigation has been opened:
The U.S. ambassador to Australia, Arthur B. Culvahouse Jr., issued a statement of support for the news media on Tuesday, although he did not directly address the Channel 7 journalists.
... On Wednesday, the day after this article was published online, the acting chief of the United States Park Police, Gregory T. Monahan, issued a statement: “As is consistent with our established practices and procedures, two U.S. Park Police officers have been assigned to administrative duties, while an investigation takes place regarding the incident with the Australian press.”
In a recent press conference, White House Press Secretary Kayleigh McEnany has defended the officers and denied that they used "tear gas" or rubber bullets:
Ms Brace and Mr Myers, who were doing a live cross back to Australia when they were struck, said they were also shot with rubber bullets and struggled to breathe after tear gas was fired into the crowd.
Ms McEnany rejected that and said the police had "a right to defend themselves".
"No tear gas was used and no rubber bullets were used," Ms McEnany said.
When a reporter countered by asking if "chemical agents were used" she replied: "So, again, no tear gas was used, no rubber bullets were used". Ms McEnany said the protesters in the park were told three times over loudspeakers they needed to move, became unruly and threw bricks and frozen water bottles at police.
"The officers had no other choice than, in that moment, to act and make sure that they were safe and that the perimeter was pushed back," she said.
No, so far I can find no direct acknowledgement of this issue coming from the Trump administration to date. The NY Times noted on June 1:
The arrest of the CNN team drew criticism from First Amendment advocates and an apology from Minnesota’s governor, but there have been dozens of other instances of journalists receiving rough treatment at the hands of police officers while covering the protests.
On Sunday, Mr. Trump blamed the “Lamestream Media” for the protests in a tweet, calling journalists “truly bad people with a sick agenda.”
Not to defend this silence, but one could argue that a more immediate response at the state level might be expected prior to any federal intervention. However the ACLU has already filed a federal lawsuit against the city of Minneapolis regarding the arrest of Jared Goyette, a freelance reporter.